Processes for recovering oil from carbonaceous material such as oil shale, typically utilize particles of a size of about one-half inch to 31/2 inches diameter. Particles of about one-half inch diameter and less, which are commonly referred to as fines, are removed from the feed stock, since they can cause channeling in the retort wherein the fines fuse and block the retorting gas flow except along limited areas where there is consequent overheating. Such fines, which are typically particles less than one-half inch diameter and wherein the average fines size is about one-quarter inch, may represent about 10% of the oil shale. The inability to effectively utilize such fines wastes an appreciable portion of the mined oil shale, and also constitutes a waste that may be difficult to dispose of. Among the many reasons for the difficulty in disposal are the large quantities involved. Also disposal presents problems because of the presence of organic material that may seep into the environment when the waste is buried, and because the dust present in the fines may increase the cost of handling it.